Apparatus for temperature regulation



M. FRISCH APPARATUS FOR TEMPERATURE REGULATION July 22, 1952 Filgd Aug. 50, 1946 INVENTOR 9 ATTORNE+ M. FRISCH APPARATUS FOR TEMPERATURE REGULATION July 22, 1952 2 SHEETSSHEET 2 Filed Aug. 30, 1946 INVENTOR Paten ted July 22, 1952 APPARATUS FOR TEMPERATURE REGULATION Martin Frisch, New York, N. Y., assignor to Foster Wheeler Corporation, New York, N. Y., a

corporation of New York Application'AuguSt 30, 1946, Serial N0. 694,116

This invention relates to temperature regulation and more particularly pertains to the control of the temperature of superheated vapor. The present invention provides a method and apparatus for controlling the temperature of superheated vapor by desuperheating the same through the introduction of condensate thereinto which condensate is produced by condensing a portion of the purified vapor before itsv introduction into the superheater. The-condensate is produced, in the present invention; at a'point prior to the point of introduction of the vapor into the inlet of the superheater. The condensate consists partially of minute droplets in suspension in vapor, which is introduced into the inlet of the superheater, and partially of liquid condensate which is introduced into the superheater at an intermediate point.v Thus the final vapor temperature may be controlled, or it may be maintained constant under varying loads imposed on the generator, by controlling the amount of condensed vapor delivered to the superheater. The invention will be disclosed as applied to the control of temperature of superheated steam but it will be understood that the invention is capable of application to the temperaturecon trol of vapors generally.

In accordance with the embodiment of the present invention disclosed, steam is condensed by a condenser in the inlet header of a superheater. The condensate collected in the lower portion of said header is conducted to an intermediate header connected to the superheaterintermediate the inlet and outlet thereof while steam with suspended droplets of water entrained thereinis conducted from the upper portion of the inlet header to the inlet end of the superheater tubes. The condensate is thereby distributed over a large portion of the superheater and the condensate introduced into the'interm'ediate header will be vaporized in the superheater within a relatively short distance. With the present invention, the superheated steam temperature is controlled by adding. chemically pure condensate to the steam. "The amount of condensate introduced into the steam is governed by controlling the flow. of condensing medium through the condensing surface thereby governing the temperature of the surface. f

' The invention will be understood from the following description when considered in connection with the accompanying drawings in which:

Fig. 1 is a more or less diagrammatic representation of a steam generator in partial vertical section embodying' a preferred form of the invention, and

Claims. (Cl. 122:479)

- Fig; 2 is a sectional view taken on the line 2--2 ofFig.l. I

1 Like characters of reference refer to the same or similar parts throughout the views.

Referring to the drawings, the reference numeral I0 designates the setting of the upper part of a steam generator having a combustion chamber II fired by burner means, not shown, and

comprising a main upper steam and water drum I2 and another upper drum I3. The drums I2 and I3 are connected by a group of steam circulator tubes I4 and a group of water circulator tubes I4. Upper'drum I2 is in communication with lower water drum I5 through a bankrof steam generating tubes I5 with which gases of combustion from the chamber I I flow in heat exchange relationship. Circulator tubes I6 connectthe lower drum I5 with the upper drum I3. Feed water is delivered to the drum I2 through a feed water pipe I! controlled by a valve I8. In the form of the invention shown, a steam purifying device such as a steam dryer I9 is disposed within the steam space of the drum I2, while the purified steam is withdrawn from said drum throughsaturated steam outlet conduits 20.

A superheater 2| ispositioned within a gas pass. or heating zone 2| which is bounded in part by the bank of steam generating tubes I5 and the circulator tubes I6 and I4; Superheater 2| comprises a plurality of inlet tubes 22 connected at one end to an inlet header 23 and at the opposite end to an intermediate header 24. The inlet tubes 22 are connectedto the upper portion of the inlet header 23 and extend downwardly into the heating zone 2| thence upwardly to the intermediate header 24 where they are connected to the lower part of said header. A plurality of outlet tubes 25 comprise an outlet section of the superheater 2| which tubes are connected at one end thereof to the lower por tion of the intermediate header 24 and extend downwardly into the heating zone 2| then upwardly to an outlet header 26. Gases of combustion flow in heat exchange relationship with the superheater 2| in passing from the combustion chamber II through the heating zone 2| to the tube bank I5 which gases, after flowing in heat exchange relationship with the tube bank I5, pass outwardly from the setting I0 through a gas outlet passage 50.

Inlet header 23 receives saturated steam through saturated steam lines 20 and is provided with condensing surface 21 which, as shown, comprises a group of return bend tubes 28, the inlet ends of which are in communica- 3 tion with an inlet chamber 29 (Fig. 2) which receives condensing medium, through conduit 30. The outlet ends of the tubes 28 are in communication with an outlet compartment 3| having an outlet through outlet conduit 32. duit 32, as shown, is in communication at'its oppositeend with feed water conduit l1. C'ondensate is conducted from the inlet header '23 to intermediate header 24 by drain tubes 33, one end of which tubes are connected to the lower portion of the inlet header. The opposite end of the drain tubes is connected to an atomizing nozzle 33' which nozzle is in communication with the intermediate header 24 so that condensate in an atomized state is introduced thereinto.

Flow of condensing medium throughconduit 30 to tubes 28 of condensing surface 21 is controlled by a valve 34. As shown, operation of valve 34 is controlled in response to temperature changes in the superheated steam leaving superheater outlet header 26 through the superheated steam outlet conduit 35. Such temperature changes are transmitted from the outlet =conduit 35 through 'line 36 to Sylphon'be'1lows '31 connected-to one end of lever arm 38 whi'ch operates a pilot 'valve 39. Lever arm 38 is connected at its end by links 40 and 4| to rod "42 of a piston 43 which-moves'in a relay cylinder 44. Fluid, such as oil which normally fills the relay cylinder, is led 'to pilot valve 39' through a 'fe'ed tube 45 and-is permitted to flowfrom the valve eitherthrough tube "46 to the upper portion of the cylinder 44 above the piston 43, or through tube -'41 to the lower portion of the cylinder, the different -'pathsof;flow being 'controlled by the position of valve --39. Valve 3'4 in conduit 30, which conducts cooling water to 'the condenser 21, is connected to piston 43 through a lever arm 13. V

In operation, steam entering 'thed'rum I 2 will be dried or otherwisepurified by passingfthrough the dryer T9 and will be conducted through the steam will be 'cendensed by indirect contact with water flowing through the tubes '23 from the con'du'it 35' Condensate produced in inlet header 23, which condensate consists 'rpartially of 'minute droplets in suspension in the steam and partially of liquid formed on the condensing surf-ace .ZTandfiwhich :pass'es to the lower 21301- tio'n of'the inlet'header in a *liquidphase; is delivered to the superheater -2l in two :portions. The portion which consists i'p'artially of minute droplets in suspension in steam passes outwardly of the'header 23 attheupper portion thereof and enters the superheater tubes 22 flowing downwardlyftherein'thenupwardly to enter the intermediate header 24, this portion of the condensate being vaporized in the tubes 22. L'he liquid portion of the condensate flows dow-nwardly from 'the lower portion-of the inletheader 23 through tubes '33-thence into the atomizing nozzles 33 and, in an atomized state, into the intermediate header -24. The liquid condensate mixes with andis evaporated by the steam partially superheated -in the tubes 22' and acts to de'sup'erheat said steam. Because of the difference "in temperature between saidsteam and the condensate, the evaporation on the condensate will occur -within a relatively short distance in the superheater tubes 25 into which the -mixture flows fr'cmrhe'ater 24. The how of steam through tubes 22 will be continuous dueto the natural pressuredrop from the inlet :header 23 and rod 42 are moved upwardly opening the valve 34. An additional amount of cooling waterwill flowthrough'the condenser tubes 28 and :a greater amount of liquid condensate will be produced in the superheater inlet header 23 with the result that more condensate will flow to the intermediate header 24 thereby reducing the final temperature of the superheated steam until the desired steam temperature is attained. If the temperature of the superheated steam falls below a predetermined value, the operation will be reversed. The temperature controller will operate to move valve 34 toward closed position until the temperature of the steam has been increased to the -predetermined value. During operation feed water is always available in adequate quantities through line I in which the valve It may be controlled in any desiredmanner.

Any suitable type of condenser or condensing equipment may be utilized. Moreover; the in- VKltiOn is not limited vin its application -to any particular type of steam -'or vapor generator. A

Inasmuch as various changes may be made:

in the form, location and arrangement "of the parts of'the apparatus :disclosed'and in the-steps of the process and their sequence as disclosed Without 'departing from the :principles of the invention, it will be understood that theinvention is not :to be limited excepting by the scope of e inlet header to the outlet header, s'aid super-- heater =t1ib'es and said other -superhe'ater tubes being-disposed in heat'exchange relationship with heated gases, a condenser in the inlet header, means for supplying a condensing mediumto' the condenser, means for passing unsuperheated vapors into "the condenser so "that said vaporsflow infheat exchange relationship therewith to produce condensate and to produce a mixture of vapor and liquid, means ;for controlling the quantity of unsuperhea'ted vaporco'ndens'ed, and conduit means in communication with the lower portion of the inlet .header'and with the intermediate header through which condensate :is conducted from the inlet header into "the intermediate header so as to introduce condensate into the vapor flowing through the intermediate header, the inlet 'ofsaid 'superheaterjtubes 'co'mmunicating with the up er. portion of the inlet header'to'receive's'aid mixture of vapo'randliquid.

2. Apparatus for uperneatirr yapcr comprising a superheater having an inlet header, an intermediate header and an outlet header, superhe'afe'r tubes connecting the inlet header andthe intermediate header, other 'superheating tubes connecting the intermediate header and the outlet header thereby forming a flow path from the inlet header to the outlet header, said superheater tubes and said other superheater tubes being disposed in heat exchange relationship with heated gases, a condenser in the inlet header, means for supplying a condensing medium to the condenser, means for passing unsuperheated vapors from a vapor generator out of heat exchange relationship with a heating medium to the condenser so that said vapors flow in heat exchange relationship with the condenser to produce condensate and to produce a mixture of vapor and liquid, means for controlling the quantity of unsuperheated vapor condenser in response to the temperature of the vapor after heating in the superheater, and conduit means in communication with the lower portion of the inlet header and with the intermediate header through which condensate is conducted from the inlet header into the intermediate header so as to introduce condensate into the vapor flowing through the intermediate header to thereby control the temperature to which the vapor is heated, the inlet of said superheater tubes communicating with the upper portion of the inlet header to receive said mixture of vapor and liquid.

3. Apparatus for superheating vapor comprising a superheater having an inlet header, an intermediate header and an outlet header, superheater tubes connecting the inlet header and the intermediate header, other superheater tubes connecting the intermediate header and the outlet header thereby forming a flow path from the inlet header to the outlet header, said superheater tubes and said other superheater tubes being disposed in heat exchange relationship with heated gases, a condenser in the inlet header, means for supplying a condensing medium to the condenser, means for passing unsuperheated vapors into the condenser so that said vapors fiow in heat exchange relationship therewith to produce condensate and to produce a mixture of vapor and liquid, means for controlling the quantity of unsuperheated vapor condensed, conduit means connecting the lower portion of the inlet header and the intermediate header through which condensate is conducted between the inlet and intermediate headers so as to introduce condensate into the vapor flowing through the intermediate header, and atomizing means in communication with said conduit means and the intermediate header to atomize the condensate entering said intermediate header, the inlet of said superheater tubes communicating with the upper portion of the inlet header to receive said mixture of vapor and liquid.

4. A steam generator comprising a steam generating section including a steam drum, a superheater having an inlet header, an intermediate header and an outlet header, superheater tubes connecting the inlet header and the intermediate header and other superheating tubes connecting the intermediate header and the outlet header thereby forming a flow path from the inlet header to the outlet header, said superheater tubes and said other superheater tubes being disposed in heat exchange relationship with gases of combustion of the steam generator, a condenser in the inlet header, means for supplying a condensing medium to the condenser, means for passing steam from the steam drum out of heat exchange relationship with a heating medium to the inlet header wherein said steam passes in heat exchange relationship with the condenser to produce condensate and to produce steam having minute water droplets in suspension therein, means for controlling the quantity of steam condensed in response to the temperature of the steam after superheating, conduit means in communication with the lower portion of the inlet header and with the intermediate header through which condensate is conducted from the inlet header to the intermediate header so as to introduce condensate into the vapor flowing through the intermediate header, and

atomizing means in communication with the conduit means and the inlet header to introduce said condensate into the intermediate header in an atomized state, the inlet of said superheater tubes communicating with the upper portion of the inlet header to receive said steam having minute water droplets therein.

5. Apparatus for superheating vapor comprising a superheater disposed in heat exchange relationship with heated gases and having an inlet portion and an outlet portion, said inlet portion and said outlet portion being in communication with one another through an intermediate header so that vapor from the inlet portion flows to the outlet portion through said header, a condenser, means for supplying a cooling medium to the condenser, means for passing unsuperheated vapors into the condenser so that said vapors flow in heat exchange relationship therewith to produce condensate and to produce a mixture of vapor and liquid, conduit means in communication with the condenser and the superheater for introducing said mixture into the inlet portion of the superheater, other conduit means separate from said conduit means and in communication with the condenser so as to receive condensate therefrom and in communication with the intermediate header so as to introduce condensate into the vapor flowing through the intermediate header, and means for controlling the quantity of vapor condensed.

MARTIN FRISCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,063,441 Kerr Dec. 8, 1936 2,133,991 Kerr Oct. 25, 1938 2,207,646 Van der Ploeg July 9, 1940 2,303,146 Thompson Nov. 24, 1942 2,319,223 Frisch May 18, 1943 2,421,761 Rowand et al. June 10, 1947 

